International trade helps spread infectious diseases

Besides opening up new vistas for humans, ranging from travel to exotic places to enjoying the products and services of those distant lands, international trade and travel also increases risk of spreading infectious diseases, a study says.

"The more trade grows as a proportion of global production, the more likely it is that diseases will be spread through trade, and the higher the economic cost of resulting trade bans," said researcher Charles Perrings, professor of environmental economics at Arizona State University in the US.

An example of international trade's impact of an infectious disease came in 2001 in Britain when an outbreak of hoof and mouth disease cost some $10 billion and more than two million sheep and cattle had to be destroyed, Perrings said. 

More recently, African swine fever -- a much more serious disease of pigs - has been spread in the Caucasus region through trade in pork, pork product or through waste in trade vehicles.

"What is at risk is the food we eat, the fibres we wear and build with, and the fuels we burn," Perrings noted. 

"In addition many infectious diseases that affect animals also affect people," he added.

"Zoonoses like SARS, MERS, HIV AIDS, or highly pathogenic avian influenza, all originated in wild animals and were then spread person to person through trade and travel," he explained.

Perrings said current instruments to control infectious diseases are far from adequate.

"There are two problems to address," he said. "One is that disease spread is an unintended (external) effect of trade. To solve this problem exporters and importers need to be confronted with the risks they impose on consumers."

"The other is that the control of infectious disease is a public good - the benefits it offers are freely available to all, and so will be undersupplied if left to the market," he explained. 

"To solve this problem we need to undertake cooperative, collective control of infectious diseases at the source," Perrings said.

The study appeared in the journal Food Security.